Vol. 60.] THE VALLEY OF THE TEIGN. 333 



that in the Hampshire Basin the east-and-west axes are of post- 

 Oligocene date. 



At the same time, I do not think that the flexures which may 

 have crossed the Oligocene plain were more than broad undulations ; 

 and if the Beer Basin marks the site of one of these broad Oligocene 

 synclines. I think that its western limb may have been a continuous 

 slope up to the Dartmoor watershed. If this was the case, it is 

 obvious that the existence of such a shallow syncline would not 

 invalidate the explanation of the Valley of the Teign which has been 

 suggested in the preceding pages. 



I have thought it desirable to limit the scope of this paper to the 

 Valley of the Teign and its tributaries, and to exclude the con- 

 sideration of other rivers ; but I wish to point out the possibility 

 that the valley of the Teign Estuary may have been the work of the 

 liiver Dart. It is a fact that the general course of the Dart across 

 Dartmoor is such as to bring it to a point due west of Xewton Abbot, 

 and consequently opposite to the entrance of the Teign Estuary. The 

 Dart now makes its way off Dartmoor through a deep gorge, like 

 that of the Upper Teign : but when it was flowing over the high- 

 level surface out of which this gorge has been cut, there is no obvious 

 reason why it should not have continued its easterly course and have 

 initiated the Teignmouth Valley. In such a case, the Lemmon would 

 have been merely a tributary of the Dart, and the latter would have 

 to be regarded as the head-source of the main Oligocene river, just 

 as the Dorsetshire Erome was, at a later date, the head-water of the 

 Solent River. 1 



Discussion. 



The President said that he was glad to find that the Authors of 

 this and the preceding paper 2 were apparently inclined to refer the 

 principal surface-features of a count}- chiefly composed of ancient 

 rocks to the Tertiary Period. 



Mr. H. B. Woodward remarked that papers on river-development 

 were most difficult to follow : they reminded him of old-fashioned 

 chess-problems where you had to mate in fifty or a hundred moves. 

 He had read the paper, but had not had time to comprehend it fully. 

 When he (the speaker) resided at Xewton Abbot many years ago, 

 he thought that the Lower Teign Valley had been started by overflow 

 from the lake in which the Bovey Beds were formed. Since then. 

 Mr. Clement Reid had seen evidence for the extension of the Eocene 

 strata over the Haldon Hills, now in places 800 feet above sea- 

 level ; and the aspect of the subject had greatly changed, owing to 

 the earth-movements which had to be taken into consideration. 

 The Author, who had asked Mr. Whitaker to act as challenger, and 

 read the paper, had desired him to be the defender and reply to 

 criticisms, and he asked permission to read a few notes from the 

 Author, if they were required, later on. 



1 See A. Strahan ' Geology of the Isle of Purbeck' Mem. Geol. Surr. (1898) 

 p. 230. 



[ a C. Reid ' On the probable Occurrence of an Eocene Outlier off the Cornish 

 Coast' Quart. Journ. Geol. Soc. vol. lx (1904) p. 113.] 



